Narrow Results

We study the capillary condensation of a lattice gas with nearest neighbor attraction confined to a slit-like pore filled with frozen obstacles (matrix). First, the lattice Monte Carlo simulations were performed for a slit-like pore without obstacles. Next, the pore filled with obstacles, i.e., confined microporous medium, is prepared by adsorbing and then by quenching a hard sphere fluid in the pore of the width H. The model includes fluid-wall attraction; however, the fluid-matrix interaction is entirely repulsive. We have investigated how concentration of obstacles and the pore width H influence the capillary phase diagrams. Our numerical experiments reveal essential changes in the critical temperature and in the shape of the coexistence line with the amount of quenched obstacles.

The elastoplastic properties of plasma-sprayed Cr₃C₂–NiCr coatings were obtained through the dimension analysis and inverse analysis by combining the experimental nanoindentation tests and numerical modeling. The digital image processing technique was used to extract the pore distribution inside the coatings based on the actual microstructure. Finally, the effect of pore distribution on the coating residual stress during nanoindentation process was analyzed through simulations. The anisotropic pore microstructure shows different mechanical responses and stress propagation behaviors during nanoindentation process. The elastic modulus of the coating demonstrates anisotropy along the spraying direction and the transverse directions due to the presence of pores.

Today in the age of advanced ceramic civilization, there are a variety of applications for modern ceramics materials with specific properties. Our up-to date research recognizes that ceramics have a fractal configuration nature on the basis of different phenomena. The key property of fractals is their scale-independence. The practical value is that the fractal objects’ interaction and energy is possible at any reasonable scale of magnitude, including the nanoscale and may be even below. This is a consequence of fractal scale independence. This brings us to the conclusion that properties of fractals are valid on any scale (macro, micro, or nano). We also analyzed these questions with experimental results obtained from a comet, here 67P, and also from ceramic grain and pore morphologies on the microstructure level. Fractality, as a scale-independent morphology, provides significant variety of opportunities, for example for energy storage. From the viewpoint of scaling, the relation between large and small in fractal analysis is very important. An ideal fractal can be magnified endlessly but natural morphologies cannot, what is the new light in materials sciences and space.

The size distributions of solid particles and pores in porous media are approximately hierarchical and statistically fractals. In this paper, a model for single-phase fractal media is constructed, and the analytical expressions for area, fractal dimension and distribution function for solid particles are derived. The distribution function of solid particles obtained from the proposed model is in good agreement with available experimental data. Then, a model for approximate two-phase fractal media is developed. Good agreement is found between the predicted fractal dimensions for pore space from the two-phase fractal medium model and the existing measured data. A model for approximate three-phase fractal media is also presented by extending the obtained two-phase model.